<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title>Tab标签切换</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }

        ul {
            list-style-type: none;
        }

        .box {
            width: 400px;
            height: 300px;
            border: 1px solid #ccc;
            margin: 100px auto;
            overflow: hidden;
        }

        .hd {
            height: 45px;
        }

        .hd span {
            display: inline-block;
            width: 90px;
            background-color: pink;
            line-height: 45px;
            text-align: center;
            cursor: pointer;
        }

        .hd span.current {
            background-color: yellowgreen;
        }

        .bd li {
            height: 255px;
            background-color: yellowgreen;
            display: none;
        }

        .bd li.current {
            display: block;
            font-size: 36px;
        }
    </style>

</head>
<body>
<div class="box" id="box">
    <div class="hd">
        <span class="current">体育</span>
        <span>娱乐</span>
        <span>新闻</span>
        <span>综合</span>
    </div>
    <div class="bd">
        <ul>
            <li class="current">我是体育模块</li>
            <li>我是娱乐模块</li>
            <li>我是新闻模块</li>
            <li>我是综合模块</li>
        </ul>
    </div>
</div>
<script type="text/javascript">
    var box = document.getElementById("box");
    var spans = box.getElementsByTagName("span");
    var lis = box.getElementsByTagName("li");
    for (i = 0; i < spans.length; i++) {
        spans[i].index = i;
        spans[i].onmouseover = function () {
            for (i = 0; i < spans.length; i++) {
//                spans[i].className = "";
                spans[i].removeAttribute("class");
                lis[i].removeAttribute("class");
            }
            this.className = "current";
//            for (i = 0; i < lis.length; i++) {//下面的li部分
//                lis[i].className = "";
//            }
            var index = this.index;//this就是当前点击的spans[i]
            lis[index].className = "current";
        };
    }
</script>
</body>
</html>